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From: Frank Rowand <frowand.list@gmail.com>
To: Stephen Boyd <swboyd@chromium.org>,
	linux-kernel@vger.kernel.org, Rob Herring <robh+dt@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>, Geert Uytterhoeven <geert@linux-m68k.org>
Subject: Re: [PATCH 10/10] of/device: Don't NULLify match table in of_match_device() with CONFIG_OF=n
Date: Thu, 17 Oct 2019 12:47:59 -0500	[thread overview]
Message-ID: <6ce47827-55e4-dd15-6a05-f25a2f8a8bb7@gmail.com> (raw)
In-Reply-To: <20191004214334.149976-11-swboyd@chromium.org>

On 10/04/2019 16:43, Stephen Boyd wrote:
> This effectively reverts 1db73ae39a97 ("of/device: Nullify match table
> in of_match_device() for CONFIG_OF=n") because that commit makes it more
> surprising to users of this API that the arguments may never be
> referenced by any code. This is because the pre-processor will replace
> the argument with NULL and then the match table will be left unreferenced
> by any code but the compiler optimizer doesn't know to drop it. This can
> lead to compilers warning that match tables are unused, when we really
> want to pass the match table to the API but have the compiler see that
> it's all inlined and not used and then drop the match table while
> silencing the warning. We're being too smart here and not giving the
> compiler the chance to do dead code elimination.
> 
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Geert Uytterhoeven <geert@linux-m68k.org>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> ---
> 
> Please ack or pick for immediate merge so the last patch can be merged.
> 
>  include/linux/of_device.h | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/include/linux/of_device.h b/include/linux/of_device.h
> index 8d31e39dd564..3f8ca55bc693 100644
> --- a/include/linux/of_device.h
> +++ b/include/linux/of_device.h
> @@ -93,13 +93,11 @@ static inline int of_device_uevent_modalias(struct device *dev,
>  
>  static inline void of_device_node_put(struct device *dev) { }
>  
> -static inline const struct of_device_id *__of_match_device(
> +static inline const struct of_device_id *of_match_device(
>  		const struct of_device_id *matches, const struct device *dev)
>  {
>  	return NULL;
>  }
> -#define of_match_device(matches, dev)	\
> -	__of_match_device(of_match_ptr(matches), (dev))
>  
>  static inline struct device_node *of_cpu_device_node_get(int cpu)
>  {
> 


Acked-by: Frank Rowand <frowand.list@gmail.com>

  reply	other threads:[~2019-10-17 17:48 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-04 21:43 [PATCH 00/10] Stop NULLifying match pointer in of_match_device() Stephen Boyd
2019-10-04 21:43 ` [PATCH 01/10] leds: pca953x: Use of_device_get_match_data() Stephen Boyd
2019-10-06 12:15   ` Jacek Anaszewski
2019-10-07  8:01   ` Geert Uytterhoeven
2019-10-13 12:10   ` Pavel Machek
2019-10-14 17:50   ` Andy Shevchenko
2019-10-14 20:54     ` Stephen Boyd
2019-10-15  9:02       ` Andy Shevchenko
2019-10-15 22:41         ` Stephen Boyd
2019-10-16 13:46           ` Andy Shevchenko
2019-11-04  9:09   ` Pavel Machek
2019-10-04 21:43 ` [PATCH 02/10] media: renesas-ceu: " Stephen Boyd
2019-10-09 12:54   ` Mauro Carvalho Chehab
2019-10-09 13:14     ` Jacopo Mondi
2019-10-04 21:43 ` [PATCH 03/10] rtc: armada38x: " Stephen Boyd
2019-10-07 13:53   ` Alexandre Belloni
2019-10-04 21:43 ` [PATCH 04/10] drivers: net: davinci_mdio: " Stephen Boyd
2019-10-04 21:43 ` [PATCH 05/10] serial: stm32: " Stephen Boyd
2019-10-05  6:53   ` Greg Kroah-Hartman
2019-10-04 21:43 ` [PATCH 06/10] usb: usb251xb: " Stephen Boyd
2019-10-05  6:53   ` Greg Kroah-Hartman
2019-10-04 21:43 ` [PATCH 07/10] ASoC: jz4740: " Stephen Boyd
2019-10-07 13:03   ` Applied "ASoC: jz4740: Use of_device_get_match_data()" to the asoc tree Mark Brown
2019-10-04 21:43 ` [PATCH 08/10] spi: gpio: Look for a device node instead of match Stephen Boyd
2019-10-07 13:03   ` Applied "spi: gpio: Look for a device node instead of match" to the spi tree Mark Brown
2019-10-04 21:43 ` [PATCH 09/10] hwmon: (lm70) Avoid undefined reference to match table Stephen Boyd
2019-10-04 23:03   ` Guenter Roeck
2019-10-04 21:43 ` [PATCH 10/10] of/device: Don't NULLify match table in of_match_device() with CONFIG_OF=n Stephen Boyd
2019-10-17 17:47   ` Frank Rowand [this message]
2019-10-17 20:24     ` Rob Herring
2019-10-17 20:48       ` Stephen Boyd

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